A number of different style trenching devices have been developed over the years such as those shown in the following U.S. Pat. No. 1,006,758, G. Karass, Lawn Edge Trimmer; U.S. Pat. No. 1,400,627, C. Rosel, Lawn Edging Machine; U.S. Pat. No. 1,544,359, J. Tolbert, Sidewalk Edger; U.S. Pat. No. 1,547,386, F. A. Hanson, Turf Edger; U.S. Pat. No. 1,622,998, A. L. Foster, Lawn Edger.
None of these patents shows a kick-type cutter capable of producing a trench having a straight side. This is important for imbedding an edger strip in the trench to define the edge of a lawn adjacent to a garden or shrubbery section of the yard.
All of the prior art known to Applicant consists of the devices shown in the above listed patents and is generally used for a different purpose. None of the trimmers illustrated in these patents shows a device specifically adapted for receiving a trim strip and providing a firm wall against which the trim strip can be positively supported when backfilled on the opposite side of the strip.